Estimated delivery times for Apple's 21.5" iMac begin slipping

New orders of Apple's 21.5-inch desktop iMac are now advertised to ship in 2 to 3 weeks to U.K. customers, suggesting production problems remain for the all-in-one desktop.

Previously, new orders were scheduled to ship in 7 to 10 business days before the estimates slipped on Monday. However, Apple's U.S. store continues to advertise shipping times of 7 to 10 days.

The larger 27-inch iMac is still advertised to ship in 3 to 4 weeks in both Apple's U.S. and U.K. stores.

The new all-in-one desktop is said to have been met with production issues when it launched late last year. Those apparent problems have continued into 2013, as availability remains limited.

AppleInsider was also first to report earlier this month that Apple's reseller channel was completely out of stock of the 21.5-inch model. If the longer shipping times from the U.K. are any indication, the company may not have had much success in improving production to keep up with demand.

Analyst Ming-chi Kuo of KGI Securities revealed in August, months before the new iMacs were unveiled, that production issues were likely. It was said that the screen lamination process in building the new desktops is difficult, particularly with the larger 27-inch model.

Apple CEO Tim Cook also publicly stated in October that his company would face a significant shortage of iMacs in the December quarter. However, no indication was given that the company expected any issues to spill over into calendar 2013.

Cook will likely shed more light on the iMac supply situation this Wednesday during his company's quarterly earnings conference call. Analysts expect Apple shipped 5 million Macs in the quarter, a year over year decrease mostly attributed to limited supply of the new iMacs.